Which of the following facial regimen products is recommended for dry skin due to an unhealthy acid mantle?

For individuals experiencing dry skin attributed to an unhealthy acid mantle, a moisturizing lotion is the most appropriate product. The acid mantle acts as a protective barrier on the skin, helping to retain moisture and shield against environmental irritants and bacteria. When this barrier is compromised, the skin can become dry and vulnerable.

A moisturizing lotion is specifically formulated to hydrate the skin and restore moisture levels, helping to repair and protect the acid mantle. These lotions often contain emollients and humectants that not only provide immediate hydration but also enhance the skin’s ability to draw in and hold moisture over time.

In contrast, exfoliants are designed to remove dead skin cells and can sometimes exacerbate dryness if used excessively or on compromised skin. Toners, while they can help balance the skin's pH, are not primarily used for hydration and may contain alcohol or astringent components that could further dry out the skin. Cleansing gels, depending on their formulation, might not provide the necessary hydration that dry skin requires and could be more suitable for oily or combination skin types.

Overall, a moisturizing lotion directly targets the issues associated with dry skin due to an unhealthy acid mantle, making it the best choice in this scenario.